Fibrous material



May 12, 1942. R. ETZKORN FIBROUS MATERIAL 1 Filed Feb. 4, i938 Patented May 12, 1942 UNITED STATES PATENT OFFICE Itudoli. Etzkom, Murg, Baden, Germany Application February 4, 1938, Serial No.'188,764 In Germany February 9, 1937 .3Claims.

Further objects and particulars of my inven tion will be clear from thefollowing detailed description of some examples of my novel packing material in connection with the accompanying drawing, showing by way of example and schematically in Fig. 1 an axial section of a stuffing box provided with my novel packing material and in Fig. 2 av cross-section of one capillary fibre of my novel packing material, on a greatly enlarged scale.

As will be seen from Fig. 1, a rotaryshaft or reciprocating rod l is packed in normal manner by a stuifing box comprising a casing 2 and a press-member 4 which can be moved into the inner cylindrical bore of the casing 2 by means of screws 8. Located in the annular space between the shaft and the inner walls of the casing 2, in the manner known per se, is the packing material comprising cords 3 of a square cross section composed of a plurality of threads 1..

Each thread 1 in turn consists of a great number, for instance, 1000 to 10,000 or more capillary fibres which according to my invention contain a lubricating substance, such as, for instance, oil, fat, tallow, wax or graphite, extending throughout the fibrous material, in a finely distributed form.

Fig. 2 shows, in a greatly enlarged cross-sectional view, a single capillary fibre, consisting of mall particles 5 of lubricating substances and .a skeleton material 6 consisting, for instance, of regenerated cellulose.

The manufacture of the artificial fibrous material is based on the solution of cellulose or cellulose compounds in suitable solvents or soluble chemical compounds. This spinning material is then introduced into a gaseous or liquid precipitating bath through a number of time orifices the width of which depends upon the kind of spinning process employed. The cellulose or.

cellulose compound is thereby precipitated in the form of a thread orfilament'which can be worked up into a textile fabric. Ifnow one or more of the aforesaid protective substances which are most suitable for incorporation in soft packings,

for example finely divided graphite or graphite and oil, are mixed with the spinning liquid in a quantity which is so great that the amount of cellulose'or cellulose compound present is just sufilcient to form a thread which still has sumcient strength to be worked further, there is then obtained an artificial fibrous material of which the smallest particles of its structure are filled and combined with the protective agent. The method of manufacturing the material is not limited in any way as regards the chemical process adapted. Useful threads can be obtained both by the viscose and super-ammonia process; the nitrate and acetate processes are also suitable and any spinning process which allows the protective substances to be added in sufficiently large quantity to the spinning solution may be employed. The threads or fibres thus obtained may be combined to a packing material in any suitable manner; I contemplate, for example, to produce the packing of many short threads ,or fibres felted together in the form of a substance similar to lap. According to a pre- Iii ferred modification'the said short artificial fibres may be spun in the form of continuous threads as known in the textile industries and beused in the form ofcords, strings, twines or the like obtained by twisting such threads. Also, a packing may be made of slubbings or rovings comprising many ,parallelly running practically endless fibres. The threads may have'a round or circular cross-section, such as obtained by pressing or squeezing a solution through round nozzles and then solidifying the fibre. By way of alternative, the single fibre may have an oval or rectangular cross-section so as to form a narrow band. Such band-shaped fibres may be produced by pressing or squeezing a spinning solution containing the lubricant through slot-shaped nozwithin wide limits. For example, the single thread may have a thickness of 1-10 denier (that is to say 9000 meters of such a fibre would have a weight of 1-10 grams) or I may use substantially thicker fibres having, for example, a diameter of 0.2 to 0.5 mm. and more.

The size of the particles of oil, fat, graphite or like lubricants depends on the thickness of the capillary fibre and the manner in which the same is produced.

Very thin fibres containing relatively coarse embeddings can be produced, for instance, by

The quantity of oily substances, such as 011- or graphite incorporated invthe single fibre depends on the desired oiliness. The maximum amount will be determined by the fact that'the percentage of the substance forming the fibre,

such as regenerated cellulose or cellulose acetate or the like has to be sufllciently high as to obtain a cohering fibre. Generally, in order to ensure a satisfactory lubricating effect, the percentage of lubricating substances will not be made less than of the weight of the complete fibre. I have found that a percentage of or preferably of 25-60 percent of graphite is very favorable, although it is possible to incorporate even higher percentages of lubricating material into the fibre mass.

Where graphite is used as a lubricator, I use the same preferably in a colloidal form, for instance in the form of defiocculated Acheson graphite. Where it is intended to incorporate an oil besides a solid lubricating substance, suchas graphite, the same may be incorporated in the solution of the fibre-forming substance besides the solid substance. A very favourable lubricating effect or oiliness is obtained, if the solid substance is first finely distributed or dispersed in the oil and the suspension thus obtained is then combined with or admixed to, the spinning solution. For example, the suspension of graphite of the kind known under the trade name "Oildag may be finely dispersed in a cellulose solution, such as viscose, by intimate stirring. This cellulose solution, when formed into fibres of round or approximately rectangular crosssection, forms a fibrous substance in which small almost all substances employed in industry. An

examination of the material has also proved, for example when graphite is employed, that particles of graphite are set free very easily by friction, the result of which is that the coefiicient of friction is very small. The extremely small wear on the packed machine parts may be explained primarily by the fact that the friction is for the most part taken up by the particles of protective material, for example flakes 'of graphite, which are embedded in the basic artificial fabric, while, on the other hand, the artificial fibrous material which acts as thecarrier for the protective particles contains an extremely small proportion of mineral constituents having a grinding effect, as can be proved by the ash content of the material.

While I have herein shown and described certain preferred embodiments of my invention, I wish it to be understood that I do not confine myself to all the precise details herein set forth by way of illustration, as modification and variation may be made without departing from the spirit of the invention or exceeding the appended claims.

I claim:

1. In a stufling box a packing comprising artificial fibers and particles of graphite incorporated in and finely distributed throughout the said fibers, the percentage of graphite being above 10% of the weight of the complete fiber.

2. In a stuffing box a packing comprising artificial fibers and particles of graphite incorporated in and finely distributed throughout the said fibers, the percentage of graphite being 25-60% of the weight of the complete fiber.

3. In a stuffing box, a packing comprising artificial fibers and particles of graphite as well as of a liquid lubricant incorporated and finely distributed throughout the said fibers, the percentage of graphite being 25-60% of the weight of the complete fiber.

the scope of RUDOLF ETZKORN. 

